@njoseph afaik Telegram's client server is open-sourced. It also has two chats to offer: secret chat (e2e) and the regular chat where your messages are encrypted, but they're stored on Telegram's servers for a lot of benefits: so users can access their saved files/messages on their cloud storage offered by Telegram.Actually, Durov has written why Telegram is not e2e by default:http://telegra.ph/Why-Isnt-Telegram-End-to-End-Encrypted-by-Default-08-14

Regarding about the second condition, Telegram isn't decentralized (yet).